Preheat oven to 200'c. Line a baking tray with baking paper.Mix together the sugar and cinnamon and sprinkle over the puff pastry sheets. Press sugar into pastry with your fingers. Flip sheet over onto a clean board. Spread other side of puff pastry with jam.Starting on one side, roll half of the pastry towards the centre. Repeat, rolling from the opposite side to meet the first roll in the middle. Cut into 1cm slices. Place on prepared tray. Bake for 10 minutes. Turn and bake for another 6-8 minutes or until caramelised. Cool slightly on tray and serve warm.